The present invention relates generally to a combined piezo solenoid actuator, and more particularly to actuators with a piezo electrically coupled to a solenoid via a transformer.
Electrically controlled actuators come in a wide variety of strengths, sizes, actuation distances, force profiles, etc. Different electrical actuators fall into a number of categories, including but not limited to solenoid actuators and piezo actuators, which can include benders and/or stacks. Solenoid actuators are often the choice when relatively large travel distances are required, whereas piezo actuators can be chosen when a relatively quick-acting high force over a short distance is desirable.
In relation to internal combustion engine technology, both solenoid actuators and piezo actuators have found a number of different applications. For instance, piezo actuators can find potential application in pressure switching valves associated with fuel injection systems. In addition, the usage of solenoid actuators has been widespread in relation to a variety of valves associated with fuel injection systems. There have also been recent trends in developing technology to electronically control the opening and closing of engine gas exchange valves, including intake valves, exhaust valves and/or engine compression release brake valves. Although electronically-controlled hydraulically-actuated gas exchange valve systems appear to show promise, a purely electrical actuator for actuating gas exchange valves has been elusive. Purely electrically actuated gas exchange valves have remained problematic at least in part because many gas exchange valves require relatively high initial opening forces coupled with relatively large travel distances.
In one aspect, an actuator includes a solenoid actuator that includes a first set of electrical windings and a moveable armature. A piezo actuator includes a second set of electrical windings and a deformable portion. The first set of electrical windings and the second set of electrical windings are arranged as a transformer.